I blasted a mate of mine dead on with the Tiger while he was running on battle of arel. He flew up into the air, bounced of another vehicle and lived to run away. Sounds like a bug.
Yes, tank blasts should be a bit more effective against infantry. And especially that short little stubby anti infantry tank on bulge and that russian vs german winter map ( lots of dead tanks in the city n such). I would hit the ground just below or 2-3 feet away from an infantry with that thing, and it did absolutely no harm at all. If its an anti infantry tank ( which I think it is), then please increase the blast radius of its explosions against infantry.